An anonymous reader writes: Stone Spray is a solar-powered robotic 3D printer that can create entire buildings out of sand. The robotic device blends soil sourced on-site with a binder and then sprays the mixture onto a surface. The soil solidifies as the machine works, allow it to create furniture, load-bearing walls and support-free sculptural shapes. The device runs on solar power, and unlike other 3D printers it has the ability to print in multiple directions on both the vertical and horizontal plane.